#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>

int main() {
    int arr[4] = { 0 };
    int i = 0, j = 0;
    int max = 0;

    while (scanf("%d ", &arr[i++]) != EOF)
    {
        if (max < arr[j])
        {
            max = arr[j];
        }
        j++;
        if (j == 4)
            break;
    }
    printf("%d", max);
    return 0;
}